Method for Bioimpedance Assessment of Superficial Head Tissue Microcirculation

Area of Science:

• Biomedical Engineering
• Physiology
• Surgical Monitoring

Background:

• Assessing microcirculation is crucial for monitoring tissue perfusion and systemic hemodynamics during surgery.
• Current methods may have limitations in providing continuous, non-invasive data.
• Superficial head tissue perfusion is an important indicator during cardiac procedures.

Purpose of the Study:

• To evaluate the electrical impedance method for quantitative assessment of superficial head tissue blood supply changes during cardiac surgery.
• To compare the dynamics of impedance parameters with microcirculatory indicators from laser Doppler flowmetry.
• To determine the informativeness of electrical impedance for monitoring scalp perfusion.

Main Methods:

• Synchronous recording of electrical impedance signals and laser Doppler flowmetry during cardiac surgeries.
• Analysis of impedance parameters, including amplitude and temporal characteristics of the pulse signal.
• Correlation of impedance parameter dynamics with microvascular indicators.

Main Results:

• Consistent changes in electrical impedance parameters were observed, correlating with microvascular indicators from laser Doppler flowmetry.
• The most significant changes in impedance parameters occurred during critical physiological state transitions: anesthesia induction, cardiopulmonary bypass initiation, and termination.
• The electrical impedance method demonstrated informativeness in assessing scalp perfusion dynamics.

Conclusions:

• The electrical impedance method is applicable for quantitative assessment of microcirculation in superficial head tissues during cardiac surgery.
• This non-invasive technique offers potential for continuous, safe monitoring of tissue perfusion in the operating room.
• Electrical impedance can serve as an additional tool for comprehensive microcirculatory assessment, enhancing the accuracy of tissue perfusion monitoring.